The economic disposal of waste solids and recovery of clean water from aqueous solutions and dispersions thereof is a recognized problem. Also, the need to recover clean water and valuable solid materials from aqueous solutions and dispersions thereof is a common occurrence. Ideally, apparatuses and processes for the recovery of water from aqueous solids should provide ease of disposition of all waste constituents, avoidance of pollution, economic operation and hygienic handling, and should, in addition, yield clean water. Furthermore, in the course of recovering clean water it is desirable to obtain valuable solid products and by-products, both solid and liquid, which are either valuable in themselves or can be utilized to further the economics of the process. For purposes of this invention it is to be understood that the term "aqueous solids" is employed generically to include suspensions, dispersions, solutions and mixtures and other forms of fluid association of solids in water.
In our U.S. application Ser. No. 73,336 filed Sept. 18, 1970, once co-pending with our aforementioned application Ser. No. 318,424 and now our U.S. Pat. No. 3,716,458 titled "Process and Apparatus for Recovering Clean Water from Dilute Solutions of Waste Solids", are disclosed process and apparatus whereby dilute aqueous waste solids are concentrated by heat evaporation, and the resultant concentrated aqueous waste solids are admixed with a relatively non-volatile oil to form a mixture which is dehydrated by heat evaporation. The substantially anhydrous waste solids in oil slurry thus formed is thereafter separated into the oil phase and the waste solids phase. However, the waste solids have sorbed thereon appreciable amounts of oil which, if not recovered, will be lost to the process and contribute to unfavorable economics.